Chia sẻ 16727 của bạn Nguyễn Hoàng Trung - đã có (0) trả lời & góp ý.
- Thiết bị: How to design Ohmmeter ( Cách thiết kế đồng hồ đo điện trở)
- Hiện tượng: How to design Ohmmeter ( Cách thiết kế đồng hồ đo điện trở) điện trở đất, điện trở thấp. Tài liệu bằng tiếng anh, các bạn vui lòng dịch lại qua tiếng việt nhé.
- Kinh nghiệm sửa chữa hoặc đề nghị giúp đỡ : How to use earth resistance meter, insulation
POSTED ON 21/08/2018BY PHAN HUY
Warranty: 12 months
Contact for best price: 028. 668 357 66 - 0888 990022
This article is to learn how to use resistors to measure resistors, circuits, capacitors, electronic components offline. This article will guide us how to use earth resistance meter, insulation with step by step. If you know how to use better please comment below.
How to use earth resistance meters (How to use Ohmmeter)
PARTS AND MATERIALS
Multimeter, digital or analog
Resistors (Radio Shack # 271-312 is 500 pieces)
Diode rectifier (1N4001 or equivalent; Radio Shack Catalog # 276-1101)
Cadmium Sulphide photocell (Radio Shack # 276-1657)
Breadboard (Radio Shack # 276-174 or equivalent)
Glass of water
This experiment describes how to measure the resistance of some objects. You do not need to have all the items listed above to be able to learn about resistance effectively. In contrast, you do not need to limit your experiment to these items. However, be sure to never measure the resistance of any object or circuit "live" any. In other words, do not attempt to measure the resistance of the battery or any other significant voltage source by using a multimeter set to the "ohms" function. Not paying attention to this warning can lead to clock damage and even personal injury.
Lesson in Electrical Circuit , Volume 1, Chapter 1: "The Basics of Electricity"
Lesson in Electrical Circuit , Volume 1, Chapter 8: "DC Metering Circuit"
Identify and understand "continuous electricity"
Identify and understand "common ground about electricity"
Measurement of resistance
Resistance characteristics: exists between two points
Select the appropriate meter range
Relative conductivity of different components and materials
How to use earth resistance meter, insulation
ELECTRICAL GUIDE BACK
Resistance is a measure of the "friction" of electricity when electrons travel through a conductor. It is measured in units of "Ohm", which is represented by the Greek letter omega (Ω).
Put your multimeter into the highest resistance available. Resistance is usually indicated by the unit symbol for the resistor: the Greek term omega (Ω), or sometimes the word "ohms". Touch the two test probes of your gauges together. When you do, the clock should register 0 ohms resistance. If you are using a similar gauge, you will see the needle deviate completely when the probe is touched and return to the rest position when the probe is pulled apart.
The resistance scale on a similar gauge is printed backwards from the other scales: there is no resistance on the right hand side of the scale and infinite resistance is indicated on the left. There should also be a small adjustment knob or "wheel" on the analogue meter to correct it for the "no" resistor.
Although multimeter your ability to provide the quantitative value of the resistor measured, it is also useful for checking the qualitative continuity : with or without a power connection continuously from point to point other. For example, you can check the continuity of a rope by connecting the clock probe to the opposite ends of the wire and checking if the needle is fully moved. What would we say about a piece of wire if the ohmmeter needle did not move at all when the transducers were connected to the opposite ends?
Digital multimeters are set to "resistance" mode indicating discontinuity by displaying some non-numeric signals on the screen. Some models say "OL" (Open-Loop), while others show dashed lines.
Use your meter to determine the continuity between the holes on a breadboard : a device used for the temporary construction of the circuit where port components are inserted into the hole on the plastic mesh, spring metal The clips below each hole connect the hole to certain people. Use small pieces of 22-gauge solid brass wire, inserted into the holes of the circuit board, to connect the clock with these clips so you can test the continuity:
How to use earth resistance meter, insulation ohmmeter
An important concept in electricity, which is closely related to electrical continuity, is the common point of electricity . The general point of electricity is the point of contact on the device or in the circuit that has a negligible (tiny) resistance between them. We can say, then, that points in a breadboard column (vertical in the illustrations) are electrically common to each other, because there is constant electricity between them. By contrast, breadboard points in a row (horizontally in the illustration) are not common in electricity, because there is no continuity between them. Continuously describes the points between the touch points, while popularity describes how points are related to each other.
Giống như tính liên tục, tương đồng là một đánh giá định tính, dựa trên sự so sánh tương đối kháng giữa các điểm khác trong một mạch. Đây là một khái niệm quan trọng để nắm bắt, bởi vì có một số sự kiện liên quan đến điện áp liên quan đến điểm chung bằng điện có giá trị trong phân tích mạch và xử lý sự cố, người đầu tiên được rằng sẽ không bao giờ có điện áp đáng kể giảm giữa các điểm được phổ biến bằng điện với nhau khác.
Choose a 10,000 ohm resistor (10 kΩ) from your parts. This resistance value is indicated by a series of colors: Brown, Black, Orange, and then another color representing the accuracy of the resistor, Gold (+/- 5%) or Silver (+/- ten%). Some resistors have no color for accuracy, marking them as +/- 20%. Other resistors use five colors to indicate their value and accuracy, in which case the color of the resistor 10 k will be Brown, Black, Black, Red and the fifth color for accuracy. .
Connect the test transducer of the meter to the resistor so, and note its indicator on the resistance scale:
If the needle is very close to zero, you need to select a lower resistance range on the meter, just as you need to select an appropriate voltage range when reading the voltage of the battery.
If you are using a multimeter, you will see a nearly 10 number displayed on the screen, with a small "k" symbol on the right hand side representing the prefix for "kilo". (thousand). Some digital calibrators are manually adjusted and require the appropriate range selection, just like analog gauges. If you are like this, experiment with different conversion location positions and see which one gives you the best sign.
Try reversing the test probes connection on the resistor. Does this change the sign of the watch? This tells us about resistance of resistor? What happens when you just touch a probe on the resistor? What does this tell us about the nature of the resistance, and how is it measured? How to compare with voltage measurement, and what happened when we tried to measure the battery voltage by touching only one probe on the battery?
When you touch the clock probe to the resistor connectors, try not to touch both probes on your finger. If you do, you will measure the parallel combination of the resistor and your body, which will tend to make the clock indicator lower than necessary! When measuring a 10 kΩ resistor, this error is minimal, but it can be more severe when measuring other resistances.
You can safely measure your body's ability to resist by holding a probe with the fingers of one hand, and another with the fingers of the other hand.
Note: Be very careful with the probes, as they are usually sharpened to the point. Keep the probes along their length, not at the point! You may need to adjust the meter range again after measuring the resistor 10k ,, because your body resistance tends to be greater than 10,000 ohms hand-to-hand. Try wetting your finger with water and measure resistance with the meter . What effect does this have on the instruction? Try to wet your fingers with salts prepared using a glass of water and salt, and measure the resistance. What impact does this have on your body's resistance measured by the meter?
Resistance is a measure of friction for electron flow through an object. The more resistances between two points, the harder it is for electrons to travel (flow) between them. Because electrical shock caused by large electron currents through the human body and increased body resistance acts as a protective measure by making electrons flow through us more difficult, we can determine What about electric finger wet power? Does water increase or decrease the risk of shock to people?
Measure the resistance of a rectifier diode with a similar gauge. Try reversing the test transducer connection with the diode and measuring the power back. What impresses you as noticeable about the diode, especially in contrast to the resistor?
Take a piece of paper and draw a very heavy black mark on it with a pencil (not a pen!). Measure the resistance across the black band using your meter, placing the probe on each end of the label as follows:
Move the probe closer together on the black mark and note the change in resistor value. Does it increase or decrease with reduced probing distance? If the results do not match, you need to draw the mark with heavier and heavier pencil marks, so that it matches the density of the pencil. Does this teach you anything about resistance compared to the length of the conducting material?
Connect your watch to the poles of a cadmium-sulphide photocell (CdS) and measure the change in resistance produced by the difference in exposure. Just like the LED of a voltmeter, you may want to use a crossover jumper wire to make a connection to the component, leaving it free to keep the photocell on the light source and / or change gauges sequences:
Test the resistance of a variety of materials, just be sure not to try to measure anything that generates significant voltage, like batteries. Suggestions for materials to measure are: cloth, plastic, wood, metal, clean water, dirty water, salt water, glass, diamond (on a diamond ring or other jewelry), paper, rubber and oil.
You are viewing the article How to use ground resistance meter, insulation (How to use ohmmeter). Next article we learn about the top 5 cheap watches under $ 100 best in 2018
TK TECHNOLOGY TRADING CO., LTD
ADDRESS: 70 STREET NO 9, WARD 9, GO VAP, HO CHI MINH
Email: email@example.com or firstname.lastname@example.org
Các bạn thành viên hãy giúp đỡ cho đề nghị trên.
Trả lời, góp ý: